|Class 12 Chemistry Surface Chemistry||Mechanism of enzyme catalysis|
Mechanism of enzyme catalysis
Enzyme-catalysed reactions usually proceed in 2 steps-
E + S --> ES*
ES* --> E +P
where E- Enzyme, S- Substrate , ES*- Activated complex , P- Product
Lock and Key Mechanism- There are many cavities present on the surface of the enzyme. These cavities have a characteristic shape and active groups like –NH2, COOH, -SH, -OH etc. These are actually the active centres on the surface of the enzyme. The reactant molecules which have a complementary shape can fit into these cavities a lot like a key fitting into a lock. Due to the active centres (groups) present an activated complex also called enzyme-substrate complex is formed.
This complex decomposes to give products and the enzyme.